Heating system for one-family houses

ABSTRACT

A heating system for a group of one-family houses, characterized in that the system is adapted to be connected to either a single common heater for all of the houses, or a plurality of individual heaters, one for each house. The individual heaters are heated either by the water from the common heater or by electric inserts.

United States Patent 1191 Brosenius Oct. 1, 1974 HEATING SYSTEM FOR ONE-FAMILY 465,298 12/1891 Timby 237/13 HO S 643,535 2/1900 Robertson 237/13 2,025,341 12/1935 Curioni 237/13 1 Inventor: Karl Hlldmg Brosemus, 2,266,252 12/1941 OSIEI'hCld 219/321 Hazeliusbacken 16, Stockholm, Sweden Primary Examiner-William F. ODea M 15 Assistant ExaminerW. Tapolcai, Jr. [21] Appl. No.: 341,692 57 ABSTRACT A heating system for a group of one-family houses, [52] U.S. Cl. 237/13, 219/279 characterized in that the system is adapted to be con- [51] Int. Cl. F24d 13/04 necte to either a single common heater for all of the [58] Field of Search 237/13; 219/279, 321, 340 houses, or a plurality of individual heaters, one for each house. The individual heaters are heated either [56] References Cited by the water from the common heater or by electric UNITED STATES PATENTS Inserts- 382,384 5/1888 Prall.... 237 13 1 Claim, 3 Drawing Figures M'ENTED 1 1974 FIG. I

FIG.3

1 HEATING SYSTEM FOR ONE-FAMILY HOUSES The present invention relates to a heating system for one-family houses, which are heated by hot water radiator systems.

In view of the present fuel situation, which can be expected to prevail into the foreseeable future, there is a need for heating systems for residential houses designed in such a way, that no only large buildings but also smaller houses may be heated by alternative means of fuel (electricity, oil, and in some cases gas, coal or wood), as the supply and cost of especially electricity and oil might in future undergo considerable changes in relation to each other.

The heating systems for one-family houses now known do not comply with the combined demands for operation by alternative means of fuel (flexible systems), as well as for low operating cost and a low cost of installation.

The heating systems for one-family houses now used can be summed up as follows:

Individual oil-heating, that is a system with an oilburning heater in every individual one-family house, heating the house by means of water-radiator-system; this system is comparatively expensive in installation, but at present it offers as do other oil-heating systerns low powerand operating costs compared with electric heating. At a reasonable cost the individual oil heater can be supplied with additional devices for electric heating; however, the cheapest and most commonly used of these devices, electrically heated inserts in oil-heaters, offer a bad operating economy, as the expensive electricity is to a very high extent affected by unavoidable heat losses in such heaters caused by chimney draft through the heater. Individual oil heaters are also considered to be rather annoying through noise, dirty handling, the smell of oil in the house, etc., and besides need a certain amount of space.

For large-area central heating plants there is a common heat-producing plant serving a whole area of I one-family houses; from this plant heating and hot water is distributed through well insulated pipe conducts in a culvert system to the' individual one-family houses. In this case, the cost of the heating plant is divided between a large number of houses (say up to 200), but experience shows that the costs of the distribution pipes rise as much as tomake the total cost for each house equally high as in the case of individual oilheaters, or even higher. A large-area central heating plant for the service of a large number of houses has by necessity got to be installed outside the territory of externally in relation to at least most of the small groups of neighbouring houses (comprising, say, 4 to 10 houses), into which a large area of one-family houses can be divided. The distance from the heating plant to the individual homes will consequently be rather great in most cases, and the heat distribution pipes will have to be both wide, long and expensive.

For these same reasons a large-area central heating plant cannot easily be adapted to future electric heating of the plant, because too much of the expensive electricity power would get lost in the distribution through the long pipes. To this will be added the difficulty of justly dividing the cost of the expensive electricity power between the subscribers to the large-area central-heating system. There is also in this case no individual heater available to the private house-owner, which is often considered to be a noticeable loss.

For district heating systems the heating plant is common to a whole town area, etc., and the costs of pipe conduits will be even higher than in the case of a large-area central heating plant. On the other hand, the power cost will be more limited, but the high installation charges have hitherto considerably limited the use of district heating for small objects as represented by one-family houses. Should a district heating plant fail to operateQuilt?-@UEQ3H3I9PJ:PQWEF515W?" plant. etc.) grave general consequences may arise.

Individual electric heating of the type direct electric heating. that is by means of electrically direct-heated radiators, is at present from the installation point of view the heating system for onefamily houses that. without comparison. offers the lowest price to the builder. In Sweden the large contractig firms have for this reason given priority on a great scale to this system when building onefamily houses on behalf of other people and not having to pay the high operating costs. Electricity is convenient. clean. noiseless but expensive. at

an average about3 times more expensive per heating unit than oil-heating. If, however, the marginal costs of power stations and distribution networks paid by the community are taken into account, also the installation cost in connection with electric heating will be high, even higher than in the case of individual oil-heating and a large-area heating plant.

For direct electric heating" only electricity may be used, thus the system is very vulnerable in case of future changes in the fuel supply, such as limitations of power, damages on power stations, power failure, etc., because no other means of power can be used for this system.

For the comparison of the installation cost relating to the different known heating-systems for one-family houses please note that the builders installation cost for a one-family-house of average size amounts to about $800 a house for the system direct electric'heating (inclusive of the community-paid costs of about $2,000

a house), to about $1,800 a house for individual oilheating, to about $1,800 a house for large-area central heating plant, to about $2,000 2,500 a house for district heating.

The present invention relates to a heating system for one-family houses, which to a remarkable degree combines the advantages of the known systems without their disadvantages. The heating system according to the invention may be used for both operationally economical electric heating and fuel-generated heating by means of all kinds of fuel. Each individual one-family house has access to an electrically heated source of its own thus individual, non-smelling, noiseless and clean but it can also make use of collectively produced power-cheap fuel-generated heating. However, the houseowner is relieved of all the maintenance trouble connected with oil-heating. In spite of these advantages the installation cost of the heating system according to the invention is kept almost as low (for the builder, about $900 a house) as the system direct electric heating. Totally, the installation cost of this new system for each individual house is considerably lower than any of the central heating systems now known.

The said advantages have been arrived at by a combination of above all three primary combination components. In addition there are a number of special components.

The invention is illustrated in FIG. l3, in which FIG. 1 shows schematically the general planning of the heating arrangement comprising a heater, the common group heater, which feeds hot water to a number of hot-water containers in a group of neighbouring houses;

FIG. 2 shows schematically, on a larger scale, a hotwater container with devices for local distribution of heat from the hot-water container to the one-family house concerned, as well as those for electric heating of the container and for some special details;

FIG. 3 shows a schematic plan view of a group of one-family houses supplied with heat from the common heater;

The first of the primary combination components is represented by each individual house 2 being fitted with a heat-insulated and with a domestic hot-water heater (through-current battery or storage heater) provided hot-water container (11, FIGS. 1 2), in the shape of a low-priced container of thin sheet-iron, the water contents of which can be heated either individually electrically or collectively via a hot-water supply from a fuel-heated common to a comparatively small group of one-family houses (1, FIG. 1), which hotwater container in turn feeds heat to the water-radiator system and the domestic hot-water heater of the house concerned.

In last-mentioned respect the hot-water container operates almost exactly in the same way as an individual heater fitted locally in the house, although in the present case there is not produced any noise, dirt or smell by burning taking place on the spot for the heating of the water in the hot-water container. The said container has another important advantage as compared with a heater, namely it is not exposed to any chimney draft with consequent useless heat losses, which means that by electric heating it produces the same high useful efficiency as direct electric heating and that also the efficiency in connection with fuel-generated heating will be unusually high. In case of electric heating it also offers the advantage of enabling the electric comsumption for each individual house to be measured separately and be recorded on the electricity meter belonging to the house concerned without being mixed with the neighbours heating consumption, in addition to which no heat losses in the distribution pipes will be added to the heating cost of the house concerned.

The second primary combination component of the heating system consists of a mainly fuel-fired heater, which is common to a group of one-family houses, terrace houses or other adjacent small-house apartments the'cost then being divided between all the houses in the group and which via a continuously operating circulation pump 8 via pipes 9, l and l2, 13, FIG. 1, continuously and simultaneously is feeding all the hotwater containers in the connected one-family houses with hot water from the heater. This feeding system has the advantage that, except a thermostat in the common heater governing its heating devices (oil burner and, as a reserve, electric devices), it has one single movable part, which is the continuously operating circulation pump 8. This gives to the system both a high degree of safety in operation and a contribution to its favourable economy.

The third important combination component of the heating system consists of the arrangement of the pipes for feeding hot water from the common heater to the hot-water containers of the one-family houses. This pipe system avails itself of as compared with the large-area central heating system and with the district heating system remarkably short and in dimension thin and, by consequence, cheap distribution pipes for hot water. This has been possible partly by the heater 1, FIG. 3, having been designed for serving in common a comparatively small group of neighbouring houses, preferably only about 4-10, partly by the arrangement of the heater being positioned close to or quite near the centre (35, FIG. 3) of the connected group of houses, feeding the hot-water containers with the pump flow from the central circulation pump 8 preferably divided between at least two outgoing hot-water pipes (9,, 9, resp, FIG. 3).

Due to the number of one-family houses of the group being comparatively small, a common heater may be used which is not very different from an ordinary automatized oil-burning one-family house heater. For this reason, the common heater can be fitted in a suitably placed small space, for instance in connection with a storage building, or the like, and it can be operated in the same simple way as an ordinary one-family house heater. In spite of this, the cost of the heater with accessories (oil tank, chimney, heater space, oil burner, etc.) for each one-family house will be strongly reduced by the cost of the common heater being divided between several houses, at an average about 7 houses per group, for instance; should the group be increased in size above this average figure, the said cost counted per house will, however, decrease further rather slowly.

Due to the one-family house group, served by the common group-heater being small in number and the heater being situated close to the centre of the houses of the group, the pipes between the heater and the houses will be short; further, due to the pump flow from the circulation pump of the heater 8 being preferably divided between at least two out-going hot-water main pipes, the pump water quantities for each pipe will be small, the pipes will then not only be short but also thin in dimension. This is of great economical importance. By using thin-dimensioned pipes for the main conduits, the pipe insulations will be radically reduced in size and price and the heat losses from the main pipe conduits will be diminished; in addition, the necessary pumping power may be lower and the circulation pump smaller.

Thus, also in these related respects there will be a fundamental difference between the group-central as compared with large-area central heating plants situated externally in relation to the one-family house groups, as well as compared with district heating systems, and the pipe connections of these systems to the one-family houses concerned.

Thus, the present invention relates to a central heating system for the heating of a group of one-family houses (small houses), row houses or other neighbouring houses adapted to be heated by means of water radiators, wherein a heater common for all said houses and mainly for fuel-burning is adapted to be connected to these houses for heating by means of circulation water, hot water, which is distributed from the heater to a hot-water container, located in each house and provided with a domestic hot-water heater, heat in turn being distributed from said container to the water radiators of the house or utilized for the heating of domestic water, characterized by the fact that the heating system is provided with equipment for either individual electric heating of each separate one-family house or for collective heating of said group of one-family houses concerned from the said common heater or for a combination of both these systems, for which purpose firstly each one of said hot-water containers located in each individual house is provided both with electric inserts to enable electric heating of the water contents of the hot-water containers, and with connection facilities for the hot-water circulation from the common heater for heating the water contents of said hot-water containers, secondly, in the case of hot-water circulation heating, the hot water heated in the common heater by means of a continuously operating circulation pump through main pipe conduits and from these pipes branched-off-pipes simultaneously and continuously is distributed to all hot-water containers located in each house, the water contents of said hot-water containers being similarly continuously mixed with and heated by the hot water flowing from the heater and then after having supplied heat to the radiator circulation water and domestic water heater of the house through separate branch pipes and corresponding separate main pipes returned to the heater and to be reheated therein, thirdly said common heater is common to a comparatively small group, four to ten, of neighbouring onefamily houses andsaid heater is located close to or near the centre of the connected group of one-family houses and is adapted to feed the hot-water containers with the pump flow from the circulation pump.

Thus, in each individual one-family house there is, according to the invention, a heat-insulated and with a domestic hot-water heater provided hot-water container, which can be heated either electrically or by means of a hot-water supply from the heater common to the group of one-family houses involved, this hotwater container in turn feeding heat to the radiators and the domestic hot water.

The hotwater container 11 may be made in a very simple way and consists normally of a sheet-iron container 14, FIG. 2, for hot water, in the case of an ordinary one-family house 350-750 litres in volume. The smaller volume should be considered as normal, while the larger one possibly increased further and in such a case divided between two containers would be of interest if there should be the need of accumulating heat in connection with electricity more about this later on. The sheet-iron container 14 is provided with a heater 15 for domestic hot water, (this heater being of through-current or storage type), and the container 14 is on all sides strongly heat-insulated by means of insulation material 16. Since the sheet-iron container is not exposed to real corrosion either from flue gases or from fresh oxygen-saturated water it may, as a principle, be made of equally thin sheet-iron as is used in the radiators fed by the hot-water container (usually 1,5 mm), thus at a low cost.

The heat distribution through the house concerned from the hot-water container 11 to the water radiators 17, FIG. 2, as well as the regulating of the temperature within the house, takes place, on principle, in the same way as the heat distribution from a locally fitted heater, that is hot water is supplied by means of a local distribution pump 18, belonging to the house, from the upper part of the hot-water container at 21, is mixed via a shunt valve 19 and a shunt pipe 20 with colder return water from the radiator system, then feeds at the mixing temperature arrived at the radiators l7 and returns eventually to the hot-water container at 22.

The total amount of hot water removed from the hotwater container via pipe 21, which hot water is normally of a fairly constant temperature, that is C, can be measured with an ordinary water meter of through-current type, for instance, this meter preferably to be placed at 25 in the return pipe for colder water 22 (as the water flow through 22 is the same as the hot-water supply through pipe 21. The water flow thus measured for a certain period of time represents an approximate proportion measure of the amount of heat from the hot-water container and can thus be used for dividing the heat cost between the one-family houses within the group connected, as a proportion of the heat supply.

The shunt valve 19 may be provided with thermostate-operated automation, by means of which the temperature of the house is automatically adjusted at the value wanted.

In case of electric heating of the hot-water container 11 one may to advantage use the device, shown in FIG. 2, with totally three electric heat inserts fitted in the container, one of which suitably placed at 27 in the upper third of 11 and the other two at 28, 29 at the bottom. The total effect of all three heat inserts correspond to the maximum required heating efficiency in case of electric heating exclusively, while one insert only, 27, is'sufficient for room heating and producing domestic hot water in spring and autumn or as emergency heat in case of power failure of the central oilheating device. The electric heat inserts need not be fitted from the beginning but may be fitted in the container tank, according to need arising, in pipe sockets welded to the tank and thus available (usually 2 inches).

Switching from collective fuel-generated heat to individual electric heating is effected simply by the return pipe 12 from the hot-water container according to FIG. 2 being shut off by means of valve 33 (and the electric heat inserts connected). The hot-water circulation through the hot-water container from the common heater 1 is thus prevented.

The hot-water container is in case of electric heating in addition to the open pipe connection to the expansion vessel 37 provided with a safety valve 34, FIG. 2, or another safety device against over-pressure caused by certain adjustment failures.

In case of fuel-generated heating of the hot-water containers 111 the heat is generated in a heater 1 common to the one-family houses of the group involved, and usually oil-fired. However, the heater may also be used with gas or with solid fuel, that is wood, coke, etc., by means of an additional device.

In the following description, to begin with, it is assumed that the heater is fired by means of an automatic oil-burner 3 of a known design. The oil burner is started and stopped by means of a signal from a thermostate 6, suitably fitted at the top of the heater, which stops the oil burner 3 if the water temperature around the thermostate is rising above a fixed value, say 85 C, and starts it again when the temperature has gone down, say, 68 C below the maximum value. According to the invention, hot water flows from the top of the heater at 7 by means ofa continuously operating circulation pump 8 and is then conveyed through heatinsulated main pipes 9 via distribution pipes 10 preferably to the top of the aforementioned hot-water containers 11 in all one-family houses connected. Preferably from the bottom of the same container the hot water, now somewhat cooled off through heat flow from the container, is returned through well-insulated return pipes 12 and 13 back to the heater 1 (or, alternatively, in case of series connection, to the top of the next container). On return to the heater 1 the return water is being reheated by the oil burner as long as this is operating, that is as long as the maximum temperature of the heater does not exceed the maximum temperature value adjusted in the thermostate 6. If the burning efficiency is sufficient, the maximum temperature of the heater will thus normally oscillate between about 85 C and a lower temperature about 6-8 less. However, the temperature values may be increased or reduced by readjustment of the thermostate 6. The continuously operating circulation pump 8 continues throughout to feed this hot water to all connected hot-water containers 11. The top water in the hot-water container apart from the insignificant falls in temperature in the pipes 9 and 10 will continuously be kept at, or close to, the top maximum temperature in the heater, about 8085 C.

This feeding system offers the very great advantage of not necessitating either any valves or any other devices for the control of the temperature; the flow of hot water takes place continuously at the temperature supplied by the circulation pump 8 from the top of the heater. It should also be observed that this feeding may continue even if there has been no heat removed from the hot-water containers, which are thus kept at the maximum temperature; the result is only that circulation water of maximum temperature is circulating idly between the heater and the container and no disconnection manoeuvres are required. In a way this contributes to the "fool-proof-accentuated safety in operation of the plant.

The common group heater is preferably positioned close to or near the centre of the group of one-family houses involved in the way already described; if so, one obtains a particularly favourable arrangement of the pipe system for the conveyance of hot water between heater and house.

As has been mentioned in the introduction the common group heater should further, as a rule, be placed in some neutral space outside the private one-family houses concerned, for instance in a storage building 63, FIG. 3 owned by the group in common but centrally situated.

The common heater can be provided with an expan sion vessel 63, FIG. 1, with overflow 64 and riser pipe 65, this vessel being fitted in a frost-protected space 40 in one of the onefamily houses of the group. This expansion vessel operates exclusively for effecting the changes in volume caused by varying temperatures of the hot-water system (for instance on start or cooling down).

Another unit of the expansion system, the safety unit, functions exclusively as an overpressure protective release in the event of over-heating of the heater. The safety unit may be designed as an outlet 41 from the top of the heater, barred by means of a safety valve 42 (for instance of the type used in closed expansion vessels. The safety valve 42 can easily be fitted frostsafe close to the heater and is designed to be released only in the case of over-heating of the heater.

The heating of the central heater can be performed with one or two oil burners (3, FIG. 1). The use of two burners can offer many important advantages, however not specified here.

For further safety, the heater may also be provided with one or two electric inserts 5, operated by the same thermostate(s) 6 as the oil burners FIG. 1. This arrangement enables the stop of both oil burners without the heater being cooled down seriously, as the heating is then taken over'automatically by the electric inserts 5. This precaution gives time for repair works or a possible exchange of oil burners, for instance, when the heater and pipe system in winter-time are exposed to the risk of freezing. The combination of two oil burners and one or more electric inserts for the heater contributes to a very high degree of safe operation.

In the event of a more permanent change to mainly electricity, the present system further offers the advantage, as compared with system direct electricity, that by means of small low-cost alterations it will enable lower operation costs by making use of the cheaper night-rate electricity through the accumulation of heat. Such accumulation, as far as room-heating is concerned, is not possible with direct electric heating, as no heat accumulation can take place in the electric radiators. In the present system preferably postponed till transition to electric heating is of current interest the accumulation capacity can be considerably increased by another heat-insulated water-container being coupled to the existing hot-water container 11, thus increasing the local water store and by this means the capacity of accumulating heat. Additionally, in the event of extremely high heat loads there is the facility of increasing further the heat production by keeping the oil-fired central heater as a reserve.

The heating system described above also ensures a great many general advantages, as compared with the known central heating systems, out of which advantages have already been mentioned a low installation cost, safety in operation, adaptation to different power supplies, convenience, etc.

With electric (individual) heating according to the invention the power supply can be measured accurately and recorded on the own electricity meter of the house involved; with (collective) heating making use of cheaper types of energy (oil, etc.) the consumption may also be measured in a simple way, although the accuracy will be somewhat less than in the case of individual electric heating.

With electric heating each house has access to its own individual heating system (the hot-water container) for the heating of the house as well as for the hot-water supply; this installation is also clean, nonsmelling and noiseless.

The heating system also enables a great number of different combinations of electricity and fuel-generated heat, which it would lead too far to describe here, however.

The heating system according to the invention may also be used to advantage if the central heater 1 in FIG. 1 is exchanged for another heat generator, for instance a heat transformer to a district-heating system, a heating pump or another central heat-generator collective to the heating of the houses involved.

Neither is the invention restricted to the designs as exemplified in FIGS. 1-3 with the appropriate descriptions, but it also comprises other designs within the frame of the invention.

Note: Hot water according to this patent application means water without over-pressure, thus hot water of maximum 100 C.

What I claim is:

1. A central heating system for the heating of a group of one-family houses (small houses), row houses or other neighbouring houses which houses are heated by means of a number of water radiators, wherein a heater common for all said houses and mainly for fuel-burning is connected to these houses for heating by means of circulation water, hot water, which is distributed from the heater to a hot-water container, located in each house and provided with a domestic hot-water heater, heat in turn being distributed from said container to the water radiators of the house or utilized for the heating of domestic water,

characterized by the fact that the heating system is provided with equipment both for individual electric heating of each separate one-family house and for collective heating of said group of one-family houses concerned from the said common heater and for a combination of both these heating systems, for which purpose firstly each one of said hot-water containers located in each individual house is provided both with electric inserts to enable electric heating of the water contents of the hot-water containers, and with connection facilities for the hotwater circulation from the common heater for heating the water contents of said hot-water containers,

secondly, in the case of hot-water circulation heating, the hot water heated in the common heater by means of a continuously operating circulation pump through main pipe conduits and from these pipes branched-off-pipes simultaneously and continuously is distributed to all hot-water containers located in each house, the water contents of said hot-water containers being similarly continuously mixed with and heated by the hot water flowing from the heater and then after having supplied heat to the radiator circulation water and domestic water heater of the house through separate branch pipes and corresponding separate main pipes returned to the heater and to be reheated therein,

thirdly said common heater is common to a comparatively small group, four to ten, of neighbouring one-family houses and said heater is located close to or near the centre of the connected group of one-family houses and is adapted to feed the hotwater containers with the pump flow from the circulation pump. 

1. A central heating system for the heating of a group of onefamily houses (small houses), row houses or other neighbouring houses which houses are heated by means of a number of water radiators, wherein a heater common for all said houses and mainly for fuel-burning is connected to these houses for heating by means of circulation water, ''''hot water'''', which is distributed from the heater to a hot-water container, located in each house and provided with a domestic hot-water heater, heat in turn being distributed from said container to the water radiators of the house or utilized for the heating of domestic water, characterized by the fact that the heating system is provided with equipment both for individual electric heating of each separate one-family house and for collective heating of said group of one-family houses concerned from the said common heater and for a combination of both these heating systems, for which purpose firstly each one of said hot-water containers located in each individual house is provided both with electric inserts to enable electric heating of the water contents of the hot-water containers, and with connection facilities for the hot-water circulation from the common heater for heating the water contents of said hot-water containers, secondly, in the case of hot-water circulation heating, the hot water heated in the common heater by means of a continuously operating circulation pump through main pipe conduits and from these pipes branched-off-pipes simultaneously and continuously is distributed to all hot-water containers located in each house, the water contents of said hot-water containers being similarly continuously mixed with and heated by the hot water flowing from the heater and then - after having supplied heat to the radiator circulation water and domestic water heater of the house - through separate branch pipes and corresponding separate main pipes returned to the heater and to be reheated therein, thirdly said common heater is common to a comparatively small group, four to ten, of neighbouring one-family houses and said heater is located close to or near the centre of the connected group of one-family houses and is adapted to feed the hot-water containers with the pump flow from the circulation pump. 